ci: add auto changelog and version update workflows

[Copilot]

Ports the automated changelog and version-bump pipeline from auto-comment-blocks to valet-windows, adapted for a PHP/Composer project.

Workflows

• changelog-ci.yml — On PR merge, maps the conventional commit type in the PR title to a changelog section (feat→Added, fix→Fixed, etc.) and appends an entry under ## [Unreleased] in CHANGELOG.md. Opens (or updates) a docs: Update changelog PR. Skips PRs labelled skip-changelog, release, auto version bump, dependencies, or typed chore/ci/docs/test/etc.
• release.yml — On GitHub release (pre/full): validates semver tag, bumps version in cli/version.php via sed, renames ## [Unreleased] to a versioned heading (## [3.5.0](.../tree/v3.5.0) - YYYY-MM-DD), opens a release PR with auto-merge, waits for merge, then moves the tag to the merge commit.
• setup-labels.yml — Syncs global + local labels on dispatch or file change.

Scripts (invoked via actions/github-script)

• update-changelog.mjs — Parses PR title, builds and inserts the changelog entry; handles duplicate detection and [Unreleased] section creation.
• check-changelog-exclusions.mjs — Gates the changelog update by inspecting PR labels and commit type before any file is touched.

Config

• .github/config/labels.json — Defines skip-changelog and auto version bump labels required by the workflows.

Adaptations from auto-comment-blocks

Concern	auto-comment-blocks	Here
Version file	package.json via npm version	cli/version.php via sed
Release link format	.../releases/tag/vX.Y.Z	.../tree/vX.Y.Z (matches existing CHANGELOG style)
[Unreleased] heading	Plain ## [Unreleased]	Handles ## [Unreleased](url) variant already in the file
GitHub URL	Hard-coded https://github.com	${{ github.server_url }}

Prerequisite: auto-merge must be enabled in repo settings for the release PR to self-merge after CI.